Wheel truing device



Allg- 27; 1957Y M. FRAGR HAL 2,803,928

WHEEL TRUING DEVICE Filed July s, 1954 s sheets-sheet 1 www TTORNE YS Aug.. 27, 1957 l M. FRAGER ETAL WHEEL TRUING DEVICE s sheets-snaai 2 Filed July 6, 1954 ug.. 27 1.957 M. FRAGER ETAL WHEEL TRUING DEVICE Filed July 6, 1954 'Sheets-Sheet 5 hij United States Patent() M' WHEEL 'rRUrNG DEVICE Max Frager, Milton Stern, and Otto E. Riegner, Philadelphia, Pa., assignors to Everite Machine Products Company, Philadelphia, Pa., a corporation of Penn- Sylvania Application July 6, `1)*54, Serial No. 441,606 8 Claims. (Cl. 51-168) The present invention relates to truing devices for disintegrating wheels such as cathode wheels for electrochemical machining and abrasive wheels, particularly of the character in which it is important to true a side face of the wheel in a plane at right angles to the axis of rotation.

When reference is made herein to a disintegrating wheel it is intended to include wheels such as abrasive wheels, which act by direct abrasion and also cathode wheels or form tools which are utilized in the presence of an electrolyte and an electric current which makes the work anodic for electrochemical machining or removal of material.

It is recognized that in the case of cathode wheels the action is electrochemical rather than true abrasion and analogous to that of abrasive Wheels.

The purpose of the invention is to permit precise adjustment of the truing of a disintegrating wheel.

i A further purpose is to permit adjustment of the plane,

in which a disintegrating wheel turns, by means accessible at the edge of the face plate while the wheel is adjusted preferably by screws which extend in through the periphery or through the back of the face plate at the edge, without the necessity of providing openings in the abrasive wheel itself.

A` further purpose is to extend the adjusting screws radially inwardly and apply the adjusting or positioning force axially by load applying elements which receive their adjustment from the screws either by wedge connection, or load application by an intervening ball, or eccentric action, or distortion of the material of the face plate.

A further purpose is to extend adjusting screws diagonally and either apply adjustment directly by a wedge on'theadjusting screw or through intervening load applying elements. `Further purposes appear in the specification and in claims.` i

In the drawings we have chosen to illustrate a `few only of the numerous embodiments in Which our invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved. l

Figure 1 is a fragmentary longitudinal section of the preferred embodiment of the invention.

Figure 1a is a fragmentary enlargement of Figure 1.

Figures 2 to l2 inclusive are fragmentary enlargements similar to Figure la, but showing variations inthe wheel truing structure according to the invention.

Describing in illustration but not in limitation and referring to the drawings:

Cathode wheels and abrasive wheels are extensively used for electrochemical machining, for grinding operations andfor other abrasive ,operations in which it is irnportant to Atrue the wheel very accurately with respect the tothe axis of rotation. This is particularly important when disintegrating the work adjacent the face oftthe wheel, that is, in a plane at right angles to the axis of rotation. Cathode wheels, abrasive wheels and the like are ordinarily not obtainable with a very high degree of trueness, and in order to prevent the necessity of individually machining or truing a side of the wheel when in place on the particular shaft or arbor, it is desirable to be able to adjust the points of engagement between the face plate and the wheel. Efforts have been made in this direction, but they have necessitated providing openings through the wheel, which are objectionable both from the standpoint of weakening the wheel, complicating the construction of the wheel, and adding to the cost.

The invention is particularly applicable to wheels consisting of a metallic cup and a diamond or other abrasive layer bonded to one side face, although 'to wheels composed almost entirely of abrasive, provided a metallic washer or the like is provided on the side engaging the face plate.

The present invention is concerned with the provision of adjustments for truing purposes on the face plate which are accessible for adjustment purposes notwithstanding that the face plate is in position against the wheel. While the invention is applicable to disintegrating Wheels generally, it is concerned particularly with the truing of diamond wheels and wheels of similar character, as just explained.

In accordance with the invention, by adopting one or a series of mechanical expedients, the setting determined by adjusting screws adjustable at the edge of the face plate is made effective on the face of the face plate notwithstanding that access to the face is not possible when the wheel is in place.

Considering first the form of Figure l, we show a shaft 20, journalled at one end in anti-friction bearings, suitably ball bearings, 21 and 22 held by a housing 23 secured to a frame 24, and journalled at the other end in an anti-friction bearing, suitably a ball bearing, 25 held in a housing 26 secured to the frame. The bearings are secured at the respective ends against shoulders 27 and 28 by bearing retaining nuts 30 and 31 threaded on the shaft. At the end opposite to that carrying the disinte grating wheel, the housing is closed by a cap 32.

At the end on which the disintegrating wheel is mounted, the shaft has a tapered portion 33 which receives and engages a face plate 34, and the face plate is retained by a flange nut on a shaft portion 35.

The face plate has a hub 36, and a disintegrating wheel 37 is placed in a position on the face plate surrounding the hub and engaging the effective surface of the face 38 of the face plate. The disintegrating wheel and the face plate are locked in place by a nut 40 on the threaded portion 35 of the shaft.

The disintegrating wheel here shown `(a metal bonded diamond wheel) has a primary abrasive face 41 which should be placed accurately at right angles to the axis of rotation, and this is accomplished by a truing operation made possible by truing devices 42 distributed around the periphery of the face plate. Depending on the size of the face plate there may be 3, 4, 5, 6 or more such truing devices at circumferentially spaced positions, preferably equally distributed. .In the form shown in Figures l and la at each truing device location the face plate is drilled and threaded radially at 43 toreceive an adjusting screw 44 which has a wrench socket 45 at the outer end and a conical or tapered inner end 46 suitably at an angle of approximately 45. At right angles to` the threaded bore 43 the face plate has an opening 47 `which extends through to the face and is preferably `staked or restricted by a lip 48 at the face. A pressure element 50 is seated in the bore 47` and `consists of a1 reverse conical end 51 which is suitably a counterpart of the inner end of the screw, and a suitably reduced and curved or dome shaped pressure surface 52 which is adapted to engage the back of the abrasive wheel. As 'the screw is forced in and the pressure element is forced outwardly in operation, it may ,slightly distort or reduce the lip 4% to permit the ,pressure elment to move to the correct position 'torliold the -disinteg'rating wheel in the correct plane, i

vIt will, of course, be understood that the shaft or spindle v'20 can be driven in any suitable way by a pulley or gearing as desired, pulley 53 lbeing merely suggestive of a pulley drive.

Whilel the form of Figures l and la is a convenient and satisfactory form for applying the adjusting connection 'at right angles lto the screw, it will be evident that other forms can-be used, and several others are indicated.

While in the formation of VFigure l and la the angular application kof the adjusting force ofthe Screw is applied by means 'o'f cooperating vwedge surfaces, .in the form of Figure '2, the lconical surface 46 of the screw acts against the bell -54 which iS retained in the eXielly 'ex- 'tended bore 47, and protrudes sufficiently to make the adjustment In some cases, however, instead of using a ball or a i pressure 'element 5t) having a conical surface at the 55. The front button portion 52 of the pressure element in this form is conveniently constructed as in Figure la.

In some cases the wedge surfaces may be placed on the cooperating passage walls as in Figure 4. In this form the screw 44 has a flat end portion 57 which cngages a cooperating flat portion l58 by a U-shaped pressure element 6'0 which has a curved surface engaging a curved wedge-like or "cam-'like wall 61 disposed diago- 'v nally toward the face plate at 'the face with respect to the screw. The pressureelement at its end remote from the screw has a surface `62 which is generally in the plane of the 'face plate. By tightening or loosening the screw the surface 62 is caused to protrude more or less from the` face plateto 'engage the disintegrating wheel. In some cases it is desirable to modify the pressure 'element as shown in Figure 5 to prov-ide a relatively narrow angular conical surface S1' at the back to engage the forward cone surface 45 of the screw. In this case the pressure element has a plunger extension 63 thr'ougha reduced rbore 64 extending axially to the face plate face, the pressure element being prevented from leaving its opening by an enlarged head 65, at the innerend. f Y In some cases instead of making a diagonal cam rela- 'tionship asin the form of Figures l to 5 inclusive, an eccentric cam action will be used as in the form of Figure 6. In this form, a screw 66 in the threaded bore V43 has an eccentric cam 'end 67 which engages a pressure plunger 68 yin the axial bore 47. Of course, if desired, the pressure element can have an enlarged head to prevent it from leaving the axial bore or can be retained by a set screw as discussed later in connection with Figure 10.

InV some cases it is preferable to use an intermediate pressure transmitting element such as a ball rather than a diagonal cam or a straight acting cam.. Constructions of this kind are shown in Figures 7 and 8. ln Figure 7, the screw "70 inthe threaded bore 43 has a straight nut preferably provided 'withja central socket 71 which engages a yball 72 in the Iaxial line ofthe screw andthe ball at its side engages a pressure transmitting eler'nent Si) as shown in Figures 1 and 1in Where desired, however, the` ball may Vengage a second ball 54v as shown in Figure 8 to apply laterally adjusting pressure to the second ball, to 'adjust the abrasive wheel.

In some cases, the screw and its threaded bore may be directed diagonally as shown in Figure 9. Here a diagonally threaded bore 43' receives a screw 44 whose conically forward end 46 conforms to the angle of the plane of the face plate face and applies pressure directly to the abrasive wheel to adjust the plane. However, in Figure 10, an intermediate pressure plunger 68 is interposed between the screw and the disintegrating wheel, the pressure plunger being conveniently retained against dropping out by a set 'screw 73 which is inserted through a radial passage 74 and has adequate freedom of motion.

In some cases, the threaded bore near the edge will extend parallel to the wheel `axis at 432 near the rim of the face plate as shown in Figure 11 and in this case, a screw 74 extends through the same and has a suitably rounded adjustment end 75 to engage the abrasive wheel.

Adjustment may also be made by deforming the metal of the face plate as shown in Figure l2. As shown in this form, a screw 76, `suitably hardened, and havingv a gradual cone point 77 is jammed in a cone in a cone passage 78 in prolongation of the threaded bore. As the screw is forced in it tends to distort or bulge the side wall of vthe face plate as shown at 80 to make the proper adjustment in the plane of engagement with the `abrasive wheel.

It will be evident that the invention is applicable to any face plate adjustment surfaces especially of the character in which a particular plane of a machining element such as a -cathode wheel or an abrasive wheel is lbrought into exact relationship with some other line or plane such as an axis of rotation.

In view of our invention and disclosure, variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain al1-or part of the benefits of our invention without copying the structure shown, and we, therefore, claim all such insofar as they fall within the reasonable spirit and scope of our claims.

In view of our invention and disclosure, what we claim as new and desire to secure by Letters Patent is:

l. A device for disintegrating material, comprising a shaft, a metallic face plate rigidly secured to the shaft transverse to the shaft axis, and having threaded openings distributed around the circumference thereof and extending generally radially inwardly, a disintegrating wheel having a metallic backing portion and abrading side face perpendicular to the axis secured on the shaft with the backing portion directly adjoining the face plate, a wheel truing means including screws threaded in the openings accessible at the circumferential edge of the ,face plate while the wheel is in place against the face plate and including load applying elements subjected to pressure by the screw means and extending through openings inthe face plate to engage the metallic backing portion kof the disintegrating wheel, the wheel truing means locally bending the wheel and shaping it into a form which brings the abrading face in a plane truly -at right angles to the axis.

2. A fdevice of claim l, in which the load applying ele ments are balls.

3. A device of claim l, in which load applying elements include a plurality of load applying elements in train subject to pressure by the screw and the foremost extending through the opening in the face plate to engage the metallic backing portion of the wheel.

4. A device of `claim l, in which the screws extend for wardly from the rear of the face plate .near the edge.

5. A device of claim l, in which the screw directly engages a ball which extends through the opening in the face plate and applies pressure to the wheel yat an angle to the axis of the screw. Y n v6. A device -of claim l, in which each load applying element extends through the opening in the face plate at an angleto the axis `of the screw and applies pressure to the Wheel, the load applying element having a Wedge surface on the end remote from the wheel, and the screw having at its end adjoining the load applying element a wedge surface which applies load to the load applying element.

7. A device of claim 1, in which the `screws extend diagonally toward the face of the face plate and have Wedge surfaces for applying load to the Wheel.

8. A device of claim l, in which each screw has a Wedge surface cooperating with a wedge portion on the face plate itself, and adapted to distort the material of the face plate to position the wheel.

References Cited in the tile of this patent UNITED STATES PATENTS Peterson Nov. 15, Shannon Oct. 4, Bird June 13, Ellis June 28, Hager Iuly 28, Speicher Mar. 27, Speicher Dec. 4, Bryant Apr. 20, 

